1. Field of the Invention
This invention relates to an autonomous robot apparatus, including an emotion model, that is, the emotion, such as instinct or feeling, as modeled, and which is capable of representing the own emotion, and a method for representing the emotion.
This application claims priority of Japanese Patent Application No. 2004-001368, filed on Jan. 6, 2004, the entirety of which is incorporated by reference herein.
2. Related Art
Recently, studies and investigations are going on in the field of a humanoid robot or an entertainment robot, as a new robot apparatus, distinct from industrial robot apparatus.
A majority of conventional robot apparatus, handled as a sort of toy machines, exploit only external stimuli as a trigger for behavior selection, with a fixed relation between the user actions and the response motion. The result is that the user readily feels tired of the toy merely repeating the same response to the same external stimuli.
On the other hand, there has recently been proposed a robot apparatus having an emotion model which has modeled the emotion typified by instinct or feeling. This sort of the robot apparatus is able to vary the emotion through interactions with the environment, including the human being, to represent the so varied emotion, and hence is improved in entertainment properties.
If a user is to recognize the emotion of the robot apparatus, having such emotional model, the manner in which the robot apparatus represents its emotion is crucial. The following methods have so far been proposed for the robot apparatus to represent the emotion for the user.    (1) The apparatus includes body resources (devices) dedicated for emotion representation.    (1-1) The emotion is represented by the colors of the LEDs (light emission devices).
For example, the emotion ‘anger’ is represented by ‘red’, and the emotion for ‘sadness’ is represented by ‘blue’.    (1-2) The emotion is represented by a ‘tail’ for simulating a dog or a cat.
For example, the emotion of ‘anger’ is represented by tucking the tail upwards, while the emotion of ‘sadness’ is represented by tucking the tail downwards.    (1-3) The motion is represented by a ‘eyebrows’ for simulating the face of a human being.
For example, the emotion ‘anger’ is represented by ‘raising eyebrows’, and the emotion for ‘sadness’ is represented by ‘lowering the eyebrows’.    (2) The speech is modulated by the emotion.
For example, the emotion ‘anger’ is represented by ‘raising the pitch, rate or amplitude of the speech’, and the emotion for ‘sadness’ is represented by ‘lowering the pitch, rate or amplitude of the speech’.
These emotion representing methods permit facilitated control with advantage because the body resources used for emotion representation are isolated from the other body resources (hands, legs, head or waist in the case of a robot apparatus simulating a living body). However, these methods suffer a deficiency that the body resources usable for emotion representation are limited and hence the emotion expressing force leaves much to be desired.
If, in substitution for or in addition to the above-described emotion representing methods, the emotion representation by motions employing the body resources is possible, more abundant emotion representation presumably becomes possible to improve the entertainment properties of the robot apparatus further. Up to now, the following methods have been proposed for emotion representation by motions employing the body resources. Meanwhile, the method of (3-2) has been proposed in the Patent Publication 1, shown hereinbelow.    (3) The motions exploiting the body resources are used for emotion representation.    (3-1) The motions associated with the respective emotions are formed.
For example, for motions such as ‘bowing’ or ‘kicking’, variations added by the emotion are prepared.    (3-2) In executing the motions, the motions are modulated depending on the Emotions.
For example, in reproducing the motions, such as ‘bowing’ or ‘kicking’, a suitable frequency is superposed on a suitable body resource for real-time generation of a motion added by the emotion.
[Patent Publication 1] Japanese Laid-Open Patent Publication 2003-89085
However, with the above method (3-1), in which the body resources dedicated to emotion representation are not needed with advantage, it is necessary to prepare motion data, added by the emotion for each motion, at the outset, while the storage capacity needed for holding motion data is increased.
With the method (3-2), in which the motion data, added by the emotion for each motion, does not have to be prepared at the outset, and the storage capacity for holding motion data is not needed, the processing volume is increased with real-time motion generation.